Various interfaces and designs have been developed as operation detection units of electronic apparatus. For example, there is a technique which provides a rotary dial input device to an electronic apparatus and moves a cursor displayed on a display unit according to the rotation amount of the rotary dial input device (refer to Patent Document 1). However, since the conventional technique employs the “rotary dial” rotated physically and mechanically, there are troubles or errors caused by a mechanical abrasion. Therefore, maintenance of the operation detection unit is needed, and the durable period is short.
Therefore, techniques employing a touch sensor as an operation detection unit which is not operated by physical and mechanical rotations have been proposed (refer to Patent Documents 2 and 3). The proposed techniques arrange a plurality of touch sensors continuously, detect an operation involving movement based on contact detection by each of touch sensor elements, and perform a selection operation control for selecting one among a plurality of selection items.    Patent Document 1: Japanese Patent Laid-Open No. 2003-280792    Patent Document 2: Japanese Patent Laid-Open No. 2005-522797    Patent Document 3: Japanese Patent Laid-Open No. 2004-311196